Bury the stream--or leave an open channel? What kind of channel?
What kind of bank reinforcement is suitable to stop erosion?
With so many questions, it's been difficult to decide on the best way to repair our greenway.
I believe that the best way to proceed with our greenway is to ask:
Excavator photo thanks to Hellagood
A brain surgeon doesn't use a chain saw. The surgeon chooses tools that will ensure a good outcome--she doesn't just grab whatever is lying on top of the tool bench.
I've heard residents say that the ravine is a treasured resource, and that they want it left much as it is now. Therefore, the central issue in assuring this outcome is choosing the size of equipment that will do the construction work without collateral damage. If the equipment is going to drive down the stream, then it ought to be no wider than the stream.
When the stream in Westmorland Park was buried two years ago, the power shovel was so large they first had to build a gravel road to support it. More trees had to be cut. Remaining gravel makes it harder to re vegetate the scar. In this case, the tail wagged the dog.
So I believe that limiting the size of equipment is the first step in planning. If the job can't be done with small equipment, then redesign the job so it can be done.
On Spaight Street, street reconstruction led the the destruction of many trees. This fiasco raised the question--how can the city request bids in a way that that penalizes contractors when they cause unnecessary damage to the environment? Defining the width of the construction corridor is an obvious solution.
This tiny power shovel (a John Deer 35D) sitting on Midvale Blvd makes tracks only 5'9" wide. That's about the average width of the stream in the greenway. Add a foot to allow the shovel to turn shallow corners, so the stream can be curved. Then require the contractor to construct a path only 6'9" wide. Build penalties into the contract to discourage the contractor from making the path any wider.
If present city regulations don't allow for this kind of bid request, then let's wait until better bidding rules are in place. After all, there's no emergency here.
Let's be creative. There are ways to move construction supplies around that don't require building gravel roads. For example, the photo below shows a simple motorized monorail used by farmers in Italy to move grapes out of vinyards on steep hillsides. It's not rocket science.
Photo thanks to Tom Ayres